Honestly, if the terrain isn't too hilly, any size would be OK. After I recently sold my 60" but my Gravelys hadn't come in yet, I used my 66" quite a bit. Learn how to use the foot pedal deck lift from time to time. Going over bumps, dips, and some of your zero turns, you'll want to give the deck lift just a little nudge to keep the anti-scalp wheels from digging in.

Now is a 66" the best choice? That's another question. If you're mowing some large areas, absolutely. But if you only have an acre or so, why would you?

I have a 60 Super and it's plenty. Of course it depends on the property. If it takes you ten passes with the 60" you'd save one with the 66 .. or something like that. So if cutting say, a football field and you did alot it might save a couple passes (maybe a minute or two) it might be worthwhile.

I mow some small sh!t with my 66" But I mow alot more large areas.. We will never own another 60" machine My QOC, and discharge are so much better with my 66 I think most of it is the increased Blade speed.. I think they use the same pulleys as the 60 but 2" longer blades equates to more tip speed.. We do have the "Northern" 60" Deck which I think is the B.. it seems to miss more dandilions and the "strip" shows up more often than the 66". To answer your ? I'd get the 66" with no less than the 28 E.F.I.